2019
Authors
da Silva, JR; Ribeiro, C; Lopes, JC;
Publication
INTERNATIONAL JOURNAL ON DIGITAL LIBRARIES
Abstract
Dublin Core descriptors capture metadata in most repositories, and this includes recent repositories dedicated to datasets. DC descriptors are generic and are being adapted to the requirements of different communities with the so-called Dublin Core Application Profiles that rely on the agreement within user communities, taking into account their evolving needs. In this paper, we propose an automated process to help curators and users discover the descriptors that best suit the needs of a specific research group in the task of describing and depositing datasets. Our approach is supported on Dendro, a prototype research data management platform, where an experimental method is used to rank and present DC Terms descriptors to the users based on their usage patterns. User interaction is recorded and used to score descriptors. In a controlled experiment, we gathered the interactions of two groups as they used Dendro to describe datasets from selected sources. One of the groups viewed descriptors according to the ranking, while the other had the same list of descriptors throughout the experiment. Preliminary results show that (1) some DC Terms are filled in more often than others, with different distribution in the two groups, (2) descriptors in higher ranks were increasingly accepted by users in detriment of manual selection, (3) users were satisfied with the performance of the platform, and (4) the quality of description was not hindered by descriptor ranking.
2019
Authors
Cherri, LH; Carravilla, MA; Ribeiro, C; Bragion Toledo, FMB;
Publication
OPERATIONS RESEARCH PERSPECTIVES
Abstract
In two-dimensional nesting problems (irregular packing problems) small pieces with irregular shapes must be packed in large objects. A small number of exact methods have been proposed to solve nesting problems, typically focusing on a single problem variant, the strip packing problem. There are however several other variants of the nesting problem which were identified in the literature and are very relevant in the industry. In this paper, constraint programming (CP) is used to model and solve all the variants of irregular cutting and packing problems proposed in the literature. Three approaches, which differ in the representation of the variable domains, in the way they deal with the core constraints and in the objective functions, are the basis for the three models proposed for each variant of the problem. The non-overlap among pieces, which must be enforced for all the problem variants, is guaranteed through the new global constraint NoOverlap in one of the proposed approaches. Taking the benchmark instances for the strip-packing problem, new instances were generated for each problem variant. Extensive computational experiments were run with these problem instances from the literature to evaluate the performance of each approach applied to each problem variant. The models based on the global constraint NoOverlap performed consistently better for all variants due to the increased propagation and to the low memory usage. The performance of the CP model for the strip packing problem with the global constraint NoOverlap was then compared with the Dotted Board with Rotations using larger instances from the literature. The experiments show that the CP model with global constraint NoOverlap can quickly find good quality solutions in shorter computational times even for large instances.
2019
Authors
Koch, I; Freitas, N; Ribeiro, C; Lopes, CT; da Silva, JR;
Publication
DIGITAL LIBRARIES FOR OPEN KNOWLEDGE, TPDL 2019
Abstract
Archives have well-established description standards, namely the ISAD(G) and ISAAR(CPF) with a hierarchical structure adapted to the nature of archival assets. However, as archives connect to a growing diversity of data, they aim to make their representations more apt to the so-called linked data cloud. The corresponding move from hierarchical, ISAD-conforming descriptions to graph counterparts requires state-of-the-art technologies, data models and vocabularies. Our approach addresses this problem from two perspectives. The first concerns the data model and description vocabularies, as we adopt and build upon the CIDOC-CRM standard. The second is the choice of technologies to support a knowledge graph, including a graph database and an Object Graph Mapping library. The case study is the Portuguese National Archives, Torre do Tombo, and the overall goal is to build a CIDOC-CRM-compliant system for document description and retrieval, to be used by professionals and the public. The early stages described here include the design of the core data model for archival records represented as the ArchOnto ontology and its embodiment in the ArchGraph knowledge graph. The goal of a semantic archival information system will be pursued in the migration of existing records to the richer representation and the development of applications supported on the graph.
2019
Authors
Sampaio, M; Ferreira, AL; Castro, JA; Ribeiro, C;
Publication
Metadata and Semantic Research - 13th International Conference, MTSR 2019, Rome, Italy, October 28-31, 2019, Revised Selected Papers
Abstract
Recent initiatives in data management recognize that involving the researchers is one of the more problematic issues and that taking into account the practices of each domain can ease this process. We describe here an experiment in the adoption of data description by researchers in the biomedical domain. We started with a generic lightweight ontology based on the Minimum Information for Biological and Biomedical Investigations (MIBBI) standard and presented it to researchers from the Institute of Innovation and Investigation in Health (I3S) in Porto. This resulted in seven interviews and four data description sessions using a RDM platform. The feedback from researchers shows that this intentionally restricted ontology favours an easy entry point into RDM but does not prevent them from identifying the limitations of the model and pinpointing their specific domain requirements. To complete the experiment, we collected the extra descriptors suggested by the researchers and compared them to the full MIBBI. Part of these new descriptors can be obtained from the standard, reinforcing the importance of common metadata models for broad domains such as biomedical research. © 2019, Springer Nature Switzerland AG.
2019
Authors
Fernando, HJS; Mann, J; Palma, JMLM; Lundquist, JK; Barthelmie, RJ; Belo Pereira, M; Brown, WOJ; Chow, FK; Gerz, T; Hocut, CM; Klein, PM; Leo, LS; Matos, JC; Oncley, SP; Pryor, SC; Bariteau, L; Bell, TM; Bodini, N; Carney, MB; Courtney, MS; Creegan, ED; Dimitrova, R; Gomes, S; Hagen, M; Hyde, JO; Kigle, S; Krishnamurthy, R; Lopes, JC; Mazzaro, L; Neher, JMT; Menke, R; Murphy, P; Oswald, L; Otarola Bustos, S; Pattantyus, AK; Veiga Rodrigues, CV; Schady, A; Sirin, N; Spuler, S; Svensson, E; Tomaszewski, J; Turner, DD; van Veen, L; Vasiljevic, N; Vassallo, D; Voss, S; Wildmann, N; Wang, Y;
Publication
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
Abstract
A grand challenge from the wind energy industry is to provide reliable forecasts on mountain winds several hours in advance at microscale (similar to 100 m) resolution. This requires better microscale wind-energy physics included in forecasting tools, for which field observations are imperative. While mesoscale (similar to 1 km) measurements abound, microscale processes are not monitored in practice nor do plentiful measurements exist at this scale. After a decade of preparation, a group of European and U.S. collaborators conducted a field campaign during 1 May-15 June 2017 in Vale Cobrao in central Portugal to delve into microscale processes in complex terrain. This valley is nestled within a parallel double ridge near the town of Perdigao with dominant wind climatology normal to the ridges, offering a nominally simple yet natural setting for fundamental studies. The dense instrument ensemble deployed covered a similar to 4 km x 4 km swath horizontally and similar to 10 km vertically, with measurement resolutions of tens of meters and seconds. Meteorological data were collected continuously, capturing multiscale flow interactions from synoptic to microscales, diurnal variability, thermal circulation, turbine wake and acoustics, waves, and turbulence. Particularly noteworthy are the extensiveness of the instrument array, space-time scales covered, use of leading-edge multiple-lidar technology alongside conventional tower and remote sensors, fruitful cross-Atlantic partnership, and adaptive management of the campaign. Preliminary data analysis uncovered interesting new phenomena. All data are being archived for public use.
2019
Authors
Rocha, A; Ornelas, JP; Lopes, JC; Camacho, R;
Publication
ERCIM NEWS
Abstract
Novel data collection tools, methods and new techniques in biotechnology can facilitate improved health strategies that are customised to each individual. One key challenge to achieve this is to take advantage of the massive volumes of personal anonymous data, relating each profile to health and disease, while accounting for high diversity in individuals, populations and environments. These data must be analysed in unison to achieve statistical power, but presently cohort data repositories are scattered, hard to search and integrate, and data protection and governance rules discourage central pooling.
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